Do you know how a computer works? We use the computer in our everyday lives but not all of us know how this machine operates. Human uses the brain to think, make decisions and process information. A computer has a brain too, and the brain of a computer is the processor or the central processing unit (CPU) that processes information.
THE CENTRAL PROCESSING UNIT
The central processing unit or the CPU is the brain of the computer. All processing activities are done in the CPU. It utilises the computer memory to execute instructions from the application software and accomplish a task. For example: editing a letter, drawing a picture and sorting numbers. The processor must be connected to input devices, output devices and storage devices to carry out the above mentioned tasks.
THE INFORMATION PROCESSING CYCLE
User will input the data to be processed by the processor. The storage holds databases, files and programs. The output devices present the processed data as useful information products for the user.
INPUT
Input is any data or instructions that we enter into the computer system for processing.
There are some common ways of feeding input data into the system, which are:
• typing on a keyboard
• pointing with a mouse
CPU accepts instruction from the user and translates the instruction into readable information (decode).
PROCESS
The processing unit controls all activities within the system. For every instruction, the control unit repeats a set of four basic operations called the machine cycle:
Fetching the process of obtaining a program instructions or data item from memory.
Decoding the process of translating a program instruction into signals that the computer can execute.
Executing the process of implementing the instructions in a program.
Storing the process of writing the result to the storage or memory.
STORAGE
Storage is a location which data, instruction and information are held for future use. Every computer uses storage to hold system software and application software. When we issue a command to start the application software, the operating system locates the program in storage and loads it into memory. A storage medium, also called secondary storage is the physical material in the computer that keeps data, instruction and information. A storage device is the computer hardware that records or retrieves items to and from storage media.
OUTPUT
Output is data that has been processed into a useful form, called information. There are four types of output, which are texts, graphics, audio and video. The text consists of characters that are used to create texts, sentences and paragraphs. Graphics are digital representations of non text information such as drawings, charts and photographs. Audio is music, speech or any other sound. Video consists of images that provide the appearance of full motion.
